Physics Questions

Heat energy can be transferred by three major methods. They are 

1. Conduction,

2. Convection and

3. Radiation.

Conduction is the movement of heat through a substance by the collision of molecules

Convection occurs when particles with a lot of heat energy in a liquid or gas move and take the place of particles with less heat energy.

Radiation is the transfer of energy by means of photons in electromagnetic waves governed by the same laws. It occurs through a vacuum or any transparent medium.

According to Rayleigh's law, the intensity of scattered light varies inversely as the fourth power of its wavelength. Sunlight consists of seven colours. Of these, red has the maximum wavelength. During sunrise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon.Therefore, light other than red is mostly scattered away. Most of the red light, which is the least scattered, enters our eyes. Hence, the sun and the sky appear red.

Nuclear Force

Tensional forces normally cause normal faults.

Conduction is the movement of heat through a substance by the collision of molecules. It occurs when two object at different temperatures are in contact with each other. Heat flows from the warmer to the cooler object until they are both at the same temperature.

Silver is the best conductor of both heat and electricity among metals with a thermal conduction value of about 430 W/(mK).

Gold and copper both come respectably close to silver.

Copper being significantly less costly it is often chosen over silver in many applications.

Aluminum has a resistivity varying from 2.65 to 2.82 × 10−8 Ω m.The resistivity of copper is generally given as: 1.72 x 10-8 Ω.m.So, since resistivity of aluminium is higher than that of copper, so Power dissipated will be greater than P. this is because rest of the factors (l, A and i) are constant.

Wavelength of a wave can be measured with the distance between two nearest crest and crest or nearest troughs. It is measured as armstrong units.